Design of an online intelligent alarming system for cascading failures of group of wind farms

In China, large-scale wind power is integrated to the power grid in a concentrating way by connecting a group of wind farms together. Each wind farm is consisted of hundreds of wind turbines and covers a large geographical area. However, such a system is vulnerable to occasional faults which can easily develop into cascading failures of adjacent wind farms, making the wind farms lose most of their power in a very short time. Cascading failures have occurred several times in reality. It is urgently necessary to construct an online assistant system to detect, analyze and explain the cascading events timely and effectively. Given that Phasor Measurement Units (PMUs) are widely installed in Chinese wind farms, the dynamic process can be recorded effectively, supplemented with Supervisory Control and Data Acquisition system (SCADA) signals. In this paper, a conceptual design of an online intelligent alarming system for cascading failures of wind farms based on PMUs and SCADA is introduced. The system is justified using real data collected in wind farms.